I purchased a new cat for my Progress Hybrid the old one still works but does not light off as quickly or put off as much heat. When or what is the point when you decide it’s time to install the new one? On that line of thought the cat’s functional is to burn wood smoke at a lower wood box temperature. But it also make for a more complete burn and increases heat output at higher temperatures. So do you put the new one in for the coldest weather or wait and use it for more of the shoulder season??? My shoulder season is if above 40’ish at night or 50 daytime I just use the heat pump. The $0.50-1.00 a day in electric at these temperatures is cheaper than my time and expenses to CSS and feed the stove! I always try to keep 2 cats on hand one newer and one well used but functional. I frequently will change cat out during a reload if I’ve noticed any decrease in draft or heat output, then clean at my leasure. For the most part I know based on performance which one is in but I’ve been known to forget, any reason I couldn’t/shouldn’t weld a small # on the outside frame I.e. 1-20.
A failed or worn out cat releases excessive pollution all the time so if your cat is dead, replace it so that the stove is always burning at top efficiency and lowest emissions. I’m fighting a near dead cat right now. Wasting wood since that smoke at my cap is just unburnt fuel. This is my third dead cat on this stove and they fail at a remarkably consistent amount of time, right near the 12000 hour mark which is like 2.5 burn seasons for a full time burner. I plan to replace the dead cat and throw it in the garbage!
How do you know the cats dead? Visible smoke from the chimney? Or the temps won't go up on the cat probe? My cat is 4 years old and I can tell it's not as efficient as when new (doesn't get a hot) but I still see no smoke and it seems to still be functioning.
For me it’s the increase in smoke plus increase in thermostat setting to keep the house warm. That increase in thermostat setting makes the burn time tank. Can barely make it through night! The glass does stay cleaner when you depend on the primary fire for heat. The cat still gets hot and even glows at high settings but drops off quick at medium or lower settings. I even checked mc on my fuel today. 13-14% Doug fir. In a woodshed for 2.5 years!
I monitor the temp. above the cat. and when it becomes slow or impossible to 'light off' and will not get significantly hotter than the firebox, it is tired and needs replacement. Some people go by smoke produced during a routine burn and when it becomes visible, again, replace the cat. Both methods work but one you have to go outside during the day, the other you can determine next to the stove, even at night Brian
For us we first start to notice smoke when lighting the cat. It will go away as the cat lights off but gets to be longer and longer for the cat to light off. We are there now. I almost changed out the cat a month ago as I was noticing more and more smoke for longer periods of time. However, we did not change yet. It is lighting off better after I brushed it a bit but still taking longer to light off. I expect if and when the weather turns cold, then we will change it. But we'll still keep the old one as a spare.
Watching this thread with interest. Never had a Cat stove. Also never really heard kind words about them from my clients that do/did have them, especially when they first came out but still to this day. I know it's important to keep them clean, brush them off once in a while and that they are something like a battery, they only have so many hours in them and it's time for a new one. Highly dependent on overall design, some stoves that is every year, others every several years. My Vermont Castings Vigilant is an older stove but it was ahead of it's time in design with secondary combustion. It'll smoke for a bit after the fire is established but when set up right and with dry wood, goes to nothing but heat mirage for the last several hours, no Cat. involved, save the ones that are sleeping under it.
It’s a trade off for sure. Noncats are great at high burn rates, clean burning and lots of output. The cat stove can run hot but also run very low and burn for a long time on very little wood. If your home stays warm on that low burn rate it is fantastic to take advantage of the corresponding long burn times and constant low output. Just need to replace the cat every few years.
Funny....its been warm a couple days here so I cleaned the chimney yesterday and cleaned the rest of the stove today,and changed the cat... .back in the fall I figured it had 11000 plus on it....gave it a vinegar bath and made it to today but still passing smoke at lower settings.its a blaze king/king and this is my 3rd or 4th cat....best stove I ever seen.
SKEETER, just curious why you are running a steelcat in your king ?? I was gonna try one in mine, but everything I read over the last few years about guys going to the steelcat, said they’d go back to ceramic for the next one..
I tried to save a cat with the vinegar boil and I did get a huge improvement but it was just temporary, another few months and I was back with a dead cat. Replacement is more cost effective than the cleaning procedure. The princess cat is cheaper at just 200$. it really is nice to get a new cat. They just kick butt.
I’m one of those guys who has burned through one of each type and I saw no benefit to the steel. Potential drawback of clogging is greatly increased with steel and they cost a lot more for the same performance. I get ceramic cats now.
It seems to depend on who you ask: I prefer SS cats. to ceramic for a few reasons. #1 is they pass more flue gas for the same size cat., SS cats have much thinner walls are are less likely to clog IME. #2 There is a lot more surface area, or more 'cells' if you prefer in the same size cat. when it is SS for the above reason (the cell walls are extremely thin). #3 SS cats. are not sensitive to thermal shock and therefore do not crack / crumble / break. #4 SS cats. do not spall, which is where the very edges of the cat. facing the incoming flue gasses crumble (sort of a variant on #3 but all the cats. I have ever seen have spalling if they are ceramic). #5 SS cats. are much quicker and easier to 'light off' and so do not need to soak over a hot fire to get the ceramic up to temp. before they actually work. This is a tremendous help on reloads- I find SS cats. do not require any open bypass time or increased draft when loading a stove with a bed of coals. Even if the combustor (cat.) stalls, it will re- light quickly when a ceramic cat under the same circumstances will tend to stay stalled. Again, all in my experience, and always comparing the two types of combustor in the same stove. I say in my experience because I actually monitor and record the temps. on the stove in four places: firebox top, directly above the combustor, the stove pipe (internal, in the middle of the pipe) just before the thimble and the stove top (outside). It makes the behavior of the stove easy to see when this data is graphed, and this is what I am basing my comments on. Brian
might be a Woodstock thing or just a stove design issue. With the bk stoves, the steel cats with their tiny cells have been clogging like crazy and the ceramic cats don’t significantly physically degrade unless you do something wrong like hit it, drop it, have leaky gaskets, ice on the fuel, or fail to use the bypass. In real life, the ability of the cat to start working at 400 instead of 500 is a non issue no matter how many thermometers you have. Neither steel nor ceramic is a bad choice. The upgrade cost for steel has proven to be a waste. In my experience anyway. I tried it.
Having read all of the previous posts regarding cat life, the following has been our experience. Our stove was installed in August of 2013. We usually burn from October thru April depending on the weather of course. We have only replaced the cat once wanting to try the steel version for comparrison to what came with the stove. Note that the original cat was still working when we changed over. It just seemed to be harder to ignite. We also installed a thermocouple probe inside the stove a few inches behind the catt to help understand what was actually happening. Depending on the type of wood and size of the load, we see the temperatrures behind the combustor to be around twice the stove top temperature which I am told is typical. I have found that when the temperature inside behing the cat reaches 500, the bypass can be closed and the cat will engage. This assumes a steady fire has been established. We do regular cleaning of the combustor and once a season a thouough vinagar solution wash. I am convinced that the type of fuel one burns has much to do with combustor life. We burn a mix of different hardwood ans also mix in pine and spruce. Nothing goes into the stove until it is dry.
